TY - JOUR

T1 - Transformation of energy spectrum and wave functions on the way from a 2D-to-3D topological insulator in HgTe quantum wells

AU - Minkov, G. M.

AU - Aleshkin, V. Ya

AU - Rut, O. E.

AU - Sherstobitov, A. A.

AU - Dvoretski, S. A.

AU - Mikhailov, N. N.

AU - Germanenko, A. V.

N1 - Funding Information: The research was supported by a grant of Ministry of Science and Higher Education of the Russian Federation, Grant No. 075-15-2020-797 (13.1902.21.0024). Publisher Copyright: © 2022 American Physical Society.

PY - 2022/8/15

Y1 - 2022/8/15

N2 - A magnetotransport and quantum capacitance of the two-dimensional (2D) electron gas in HgTe/CdxHg1-xTe quantum wells of a width (20.2-46.0) nm are experimentally investigated. It is shown that the first energy subband of spatial quantization is split due to the spin-orbit interaction and the split branches are single spin, therewith the splitting strength increases with the increase of the quantum well width. The electron effective masses in the branches are close to each other within the actual density range. Magnetointersubband oscillations (MISO) observed in the structures under study exhibit the growing amplitude with the increasing electron density that contradicts to the expected decrease of wave-function overlap for the rectangular quantum well. To interpret the data obtained, we have used a self-consistent approach to calculate the electron energy spectrum and the wave function within framework of the kP model. It has been, in particular, shown that the MISO amplitude increase results from the increasing overlap of the wave functions due to their shift from the gate electrode with the gate voltage increase known as a phenomenon of the negative electron polarizability. The results obtained from the transport experiments are supported by quantum capacitance measurements.

AB - A magnetotransport and quantum capacitance of the two-dimensional (2D) electron gas in HgTe/CdxHg1-xTe quantum wells of a width (20.2-46.0) nm are experimentally investigated. It is shown that the first energy subband of spatial quantization is split due to the spin-orbit interaction and the split branches are single spin, therewith the splitting strength increases with the increase of the quantum well width. The electron effective masses in the branches are close to each other within the actual density range. Magnetointersubband oscillations (MISO) observed in the structures under study exhibit the growing amplitude with the increasing electron density that contradicts to the expected decrease of wave-function overlap for the rectangular quantum well. To interpret the data obtained, we have used a self-consistent approach to calculate the electron energy spectrum and the wave function within framework of the kP model. It has been, in particular, shown that the MISO amplitude increase results from the increasing overlap of the wave functions due to their shift from the gate electrode with the gate voltage increase known as a phenomenon of the negative electron polarizability. The results obtained from the transport experiments are supported by quantum capacitance measurements.

UR - http://www.scopus.com/inward/record.url?scp=85136202057&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.106.085301

DO - 10.1103/PhysRevB.106.085301

M3 - Article

AN - SCOPUS:85136202057

VL - 106

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 8

M1 - 085301

ER -